• Male apolipoproteins RPRC010099 and RPRC015421 induce oviposition in mated females. • These apolipoproteins are transferred to females during copulation. • Docking analysis suggests that testes apolipoproteins carry eicosanoid hormones. • First report of apolipoproteins as candidates for hormone transfer during mating. The kissing bug Rhodnius prolixus , a primary vector of Chagas disease, serves as a model for understanding insect physiology and vector-pathogen interactions. While the role of male reproductive factors in influencing female fertility is well-established in many insects, little is known about male fertility in R. prolixus. Our study examines the role of two apolipoproteins, RPRC010099 and RPRC015421, in male fertility and their potential function as carriers of eicosanoid hormones. Using RNA interference (RNAi), we silenced the genes for both apolipoproteins in male R. prolixus . The silencing of RPRC010099 led to a significant reduction of ∼60% in the number of eggs laid by mated females, while silencing RPRC015421 resulted in a ∼20% reduction. Further analysis, including molecular docking and enzyme-linked immunosorbent assays (ELISA), confirmed that these proteins are transferred from males to females during copulation and have a high affinity to eicosanoid signaling molecules, such as prostaglandin E2. Our findings demonstrate that RPRC010099 and RPRC015421 are important male fertility factors that promote female oviposition and probably act as carriers for eicosanoids. This work not only identifies a novel reproductive role for apolipoproteins but also contributes to a broader understanding of male–female interactions in insect reproduction.
Santos et al. (2026) studied this question.